A variety of technologies enable telecommunication services to be offered using Internet Protocol (IP). Commonly referred to as Voice over IP, or VoIP, such technologies enable telecommunications on any public or private IP network, including the Internet. VoIP technology permits a user to receive IP-based telecommunications services through a variety of devices, including a desktop computer, a notebook computer, an analog handset used in conjunction with a VoIP telephone adapter, a VoIP-enabled handset, or other like device.
Increasingly, mobile devices, such as notebook computers, personal digital assistants (PDAs), wireless handheld devices, wireless handset devices, or other similar mobile devices, are also being enabled to receive IP-based telecommunications services. Such services are provided by enabling the mobile device to communicate with a wireless router and access any IP-based wireless access network, such as a network based on the IEEE 802.16 (WiMAX), IEEE 802.20 Mobile Broadband Wireless Access (MBWA), Ultra Wideband (UWB), 802.11 wireless fidelity (Wi-Fi), and Bluetooth standards.
Moreover, dual-mode mobile telecommunications devices may be enabled to communicate with any IP-based wireless access network. For instance, Unlicensed Mobile Access (UMA) technology allows wireless service providers to merge cellular networks, such as Global System for Mobile Communications (GSM) networks, and IP-based wireless networks into one seamless service with one mobile device, one user interface, and a common set of network services for both voice and data. UMA technology has recently been accepted into release 6 of the 3rd Generation Partnership Project (3GPP) standard as a General Access Network (GAN). With UMA or GAN solutions, subscribers may move between cellular networks and IP-based wireless networks with seamless voice and data session continuity as transparently as they move between cells within the cellular network. Seamless in-call handover between the IP-based wireless network and cellular network ensures that the user's location and mobility do not affect the services delivered to the user. Services may be identical whether connected over the IP-based wireless network or the cellular network. UMA technology effectively creates a parallel radio access network, the UMA network, which interfaces to the mobile core network using standard mobility-enabled interfaces. The mobile core network remains unchanged. The common mobile core network makes it possible for the service provider to have full service and operational transparency. The existing service provider Business Support Systems (BSS), service delivery systems, content services, regulatory compliance systems, and Operation Support Systems (OSS) can support the UMA network without change. Service enhancements and technology evolution of the mobile core network apply transparently to both cellular access and UMA.
A number of problems exist in locating a mobile device on an IP-based wireless telecommunications network and providing location based services to the mobile device. Telecommunications service providers increasingly offer location-based services that deliver information specific to the mobile device's current location. Telecommunications service providers also wish to route certain calls, such as 911 or “emergency” calls, to an office that is geographically relevant to the user of a mobile device. Service providers who operate IP-based wireless telecommunications networks must therefore implement systems and methods that determine the mobile device's location on an IP-based wireless telecommunications network.